The television industry is continuously seeking technology improvements that will enhance the presentation of an event. In particular, producers of television sporting events seek to obtain viewers by using new video enhancement technologies. Virtual lines, a coach's chalkboard-like overlay and statistic presentation headers and footers are examples of recent technologies that are in great demand by increasingly fickle viewing audiences. Indeed, video enhancement technologies such as these are used not only in sporting events but also in news broadcasts, award ceremonies, concerts and other presentations of live events.
Sporting events have also pushed the television industry to find new ways of presenting detailed statistics about various aspects of an event. For example, the speed of a baseball pitch or the hang time of a football kick are often measured by an individual using a radar gun or a stop watch. Unfortunately, current statistic measurement systems rely on human measurement, which may be prone to error or inaccuracy. For example, because of human reaction time, a person using a stop watch to measure the hang time of a football may not start or stop the watch precisely when the ball hits the kicker's foot or the receiver's hands. In addition, current measurement methods are limited in that they only calculate one parameter, and they do not allow calculation of multiple statistics, or the relation of video enhancement to the statistics, because they rely on human judgment.
For example, U.S. Pat. No. 6,133,946 to Cavallaro et al., the disclosure of which is incorporated herein by reference in its entirety, discloses a system that may measure events within a video image, such as a hang time for a jump. However, such methods have limited applicability, as they do not provide for complex calculations such as speed, as they provide no mechanism to consider relative positions within a frame sequence. Further, they do not provide for the graphical representation of the parameters in the image sequence or in alternate image sequences, nor do they allow for presentation of the parameter in real time, as the event occurs.
As another example, U.S. Pat. No. 6,441,846 to Carlbom et al., the disclosure of which is incorporated herein by reference in its entirety, discloses a method of deriving performance statistics real time tracking of a sporting event. However, such methods are limited to the prediction of trajectories based on extrapolation, and they require real time tracking of the event.
Accordingly, we have determined that it is desirable to provide an improved measurement of determining and presenting statistics for an event in an image stream that captures the event.